In March, the Wiltshire cathedral city was the scene of the novichok poisoning of former Russian spy Sergei Skripal and his daughter Yulia, who both survived.

Admitted to hospital on 30 June, Ms Sturgess, 44, later died, while Mr Rowley, 45, was discharged on Friday, three weeks after falling ill.

Mr Rowley's brother, Matthew, told Sky News he was "ecstatic" at his brother's release from hospital, but expressed surprise at his swift recoverygiven only a few days previously he had still seemed very weak.

Mr Rowley said: "He's obviously improved in his condition.

"He was very weak. He could barely lift his head off the pillow. He had lots of tubes... and a lot of machines around him.

"Obviously he's stronger than I thought."

How does novichok affect the body?

Mr Rowley said his brother's recollection of what happened was "very vague", but added: "He definitely said to me that they found this bottle of something and Dawn sprayed it on her wrists and that he picked it up and broke it somehow - and that's how he got it on his hands."

Public Health England medical director Paul Cosford has said Mr Rowley's discharge from hospital does not pose a risk to the public.

He added: "Our advice to the public remains unchanged. Do not pick up any items such as syringes, needles, cosmetics or similar objects made of materials such as metal, plastic or glass.

"If you didn't drop it, then don't pick it up."

Image:Sergei and Yulia Skripal were poisoned with novichok in Salisbury in March